import java.util.*;
   class Example2_5 {
    public static void main(String args[]) {
    int start =0,end,middle;
    int a[] = {20165212,45,67,89,123,-45,67};
    int N = a.length;
    for(int i=0;i<N;i++ ) {
     for( int j=i+1;j<N;j++) {
      if ( a[j]<a[i]){
       int t = a[j];
       a[j] =a[i];
       a[i] =t;
      }
}
}
Scanner scanner = new Scanner(System.in);
System.out.println("输入整数，程序判断该数是否在数组中:");
int number = scanner.nextInt();
int count = 0;
end =N;
middle=(start+end)/2;
while(number!=a[middle]){
   if(number>a[middle])
    start =middle;
   else if(number<a[middle])
    end =middle;
   middle = (start+end)/2;
   count ++;
  if(count>N/2)
   break;
  }
 if(count>N/2)
   System.out.printf("%d不在数组中.\n",number);
 else
   System.out.printf("%d在数组中.\n",number);
}
}
